Captain_Peach wrote:
So what exactly is this 121 days thing. I've just bought this and if someone could tell me what happens in the least spoilerific way I would love them forever.

It'll make more sense when you reach that point but essentially when the timer hits 121 days, you're actually locked into the end game at this point, though you'll think you have plenty of time to continue playing (you'll think you have 121 days, in fact).